1. Field of Invention
The present invention relates to a system for dispensing fluids. In particular, the present invention relates to a fluid dispensing system wherein a support structure holds bulk fluid that is transferred to an enclosed chamber in a dispensing base from which chamber the fluid is dispensed. After dispensing air pressure in the enclosed chamber is equalized with the air pressure acting on the bulk fluid.
2. Description of Related Art
Conventional domestic fluid dispensers used primarily for providing heated or cooled water are usually free standing devices which dispense sterilized or mineral water from large rigid water bottles. The rigid water bottles have a large body portion and a narrow neck portion having a mouth opening, and are coupled to the water dispenser by inverting the bottle and positioning the mouth of the bottle in the chamber of the water dispenser. Air, introduced into the water bottle through the mouth, allows water to be dispensed from the inverted bottle until the water level in the chamber reaches the mouth of the bottle. Since the water bottle is rigid, once the water level in the chamber reaches the mouth of the bottle no more air can enter the bottle, so water remaining in the inverted bottle is retained in the bottle due to the difference between the air pressure external to the inverted bottle and the air pressure inside the bottle. Water is then dispensed from the chamber through a conduit attached to a valve at the opposite end from the chamber. When the level of water in the chamber falls below the mouth of the water bottle, air enters the water bottle, allowing water to flow from the bottle until the water level in the chamber again reaches the mouth of the bottle.
Although conventional domestic water dispensers are widely used, they are deficient in a number of respects. First water bottles used in the conventional domestic water dispenser usually contain a large quantity of sterilized water, typically on the order of about 5 gallons. Due to the weight and size of a bottle holding that amount of water, it is often difficult to invert and properly locate the mouth of the bottle in the chamber without spilling a quantity of the water.
Second, to prevent water from continuously flowing from the water bottle while the water bottle is inverted, the water bottles used with such water dispensers are fabricated from a thick, rigid, plastic material that can hold a vacuum without collapsing. Due to their cost, the water bottles are usually resterilized and reused after an initial use. As a result, the cost of shipping the empty water bottle back to the supplier for sterilization and reuse are adsorbed by the consumer through increased water costs.
Third, in order for the mouth of the water bottle to be positioned in the chamber of the cooler, the water bottles must have a neck, as described above. The presence of the neck, however, increases the difficulty in sterilizing the water bottles, since the neck may limit the ability of the sterilizing agents to reach all the interior parts of the bottle, even when large quantities of sterilizing agents are used. While the use of heat sterilization may overcome this problem to some extent, it is generally not possible to use heat sterilization on plastic bottles. Although, sterilization using ultraviolet light is possible, ultraviolet light sterilization may lead to an incomplete result. Particularly troublesome, once the bottle is inverted into the fluid dispenser, the outside of the neck of the bottle contacts the fluid, and it is very difficult to maintain this area of the bottle sterile.
Fourth, with the necessity of sterilizing the water bottles after each use, over time the rigid plastic water bottles may develop cracks or holes. If such failures occur while the water bottle is inverted in the water dispenser, air will enter the water bottle and allow water to flow uncontrollably from the mouth of the water bottle, allowing the chamber to eventually over flow. This water over flow can expose the purchaser's premises to the risk of water damage.
One solution to the problem of potential chamber overflow, and the necessity to make bottles of rigid materials to allow for the pressure differential described above, is to add a valve in the flow path between the bottle and the chamber. Such a valve allows the flow of water out of the bottle to be closed off so that the chamber does not overflow, thus eliminating the necessity of a rigid bottle and eliminating. Such a valve can operate automatically, opening and closing depending on the level of the fluid in the chamber.
Aided by the use of valves in the path between the bottle and the chamber, a more recent development in fluid dispensing systems has been to utilize bags rather than bottles to transport and dispense water from an otherwise conventional fluid dispensing system (“office cooler”). Such a system is described in U.S. Pat. No. 6,398,073 ('073) to Nicole, for example, which is incorporated herein by reference. The '073 patent offers a device that dispenses fluid from a disposable or recyclable bag, and thereby affords some of the benefits associated therewith. As described in the '073 patent, however, to overcome the problem of over flowing the chamber since a collapsible bag cannot hold a reduced pressure headspace (as a rigid bottle does), the device described therein requires a valve to control flow between the bag and the chamber.
An embodiment of the '073 fluid dispensing system uses fluid contained in a bag to fill a chamber from which fluid can be dispensed, and preferably uses a ballcock valve to control the flow of water from the bag into the chamber. The carrier is disposed on top of a water cooler housing and, together with a fluid filled bag positioned therein, is designed to be used as a replacement for the conventional, inverted, rigid, plastic water bottle. A spike is provided in the carrier for puncturing the bag after the bag is positioned therein. The spike includes an internal fluid passage that extends through the carrier to allow the fluid to flow from the bag, through a conduit, and into the chamber. The conduit includes the flow control valve, which allows fluid to flow from the bag into the chamber under the force of gravity when the level of fluid in the chamber drops below a desired level, and terminates the fluid flow from the bag when the level of fluid in the chamber reaches the desired level. After fluid is dispensed from the chamber through an access tap, fluid from the bag will refill the chamber to the desired level, as controlled by the valve.